1. You’re probably not addicted to the internet.

Most of what’s described as “internet addiction” is actually other addictions – to gambling or video games – that just happen to take place online. While “problematic internet use” is a real thing, feeling addicted to the internet could just be your sense of a strong habit.

Subconscious cues – time of day, reaching the end of a work project, feeling stressed and wanting to relax – can trigger your internet habit, without your even realizing it. Then you find yourself refreshing Facebook or scrolling down Reddit without even really knowing why.

In his book, The Power of Habit, Charles Duhigg describes habit loops as: trigger, habit, and reward: You feel lonely → you check Facebook → you get the reward of seeing what’s going on in your friends’ lives. You feel bored → you play 2048 on your phone → you numb yourself from boredom.

If your web habit is bothering you, pay attention to the cues that trigger your habit, and look for other things you can do – gchat a friend, go for a walk, pet your cat – that can give you the same nice feeling of reward.

2. Random rewards are really powerful.

If you train a rat to expect a treat every time he pushes a button, he’ll get a few treats and wander off. But if the rat only gets a reward sometimes, at random intervals, he’ll become obsessed with pushing that button and trying to get that treat.

Okay. So now replace pushing the button with refreshing Twitter, replace the rat treats with replies or faves, and replace the rat with yourself.

This quirk of psychology is exploited by casinos and video game designers, and it governs how you relate to the internet and social media, too. Random rewards are everywhere on the internet – new email alerts, Facebook likes, reblogs on Tumblr, and even just finding a lower price on that 20lb bag of cat litter if you just check one more site. There could be something great at any time!

3. Your brain misses its downtime.

When you’ve always got your nose in a smartphone or screen, the constant stimulation doesn’t leave time or space for your mind to wander. Our quest to avoid boredom might be costing our brains vital processing and chilling-out time.

A brain at rest isn’t really at rest – it’s processing thoughts, reflecting on experiences, and filing away memories into long-term storage. Some researchers also speculate that a lack of time for introspection could be changing our very senses of self, causing us to focus more on the concrete and external than on the inner worlds of our minds.

4. Information overload is real.

Wikipedia has plenty of space for its information, but your little brain can only hold a few thoughts at a time. When you try to stuff too much into your short-term – or “working” – memory, something has to go. The endless scrolling of Facebook or Twitter doesn’t give you a chance to process what you’ve seen – you read and read, but nothing sticks. In his book, The Shallows, What the Internet is Doing to Our Brains, Nicholas Carr writes that this overload of working memory starves our “deep” memory, where new ideas and creative synthesis happen.

5. There’s no such thing as multitasking.

Bouncing between browser windows, splitting attention between your TV, phone, and computer screens, you might feel like the queen of multitasking. But as far as cognitive psychology is concerned, there’s no such thing as multitasking. There is only task-switching. And if you’re very used to flitting from task to task – whether it’s twitter and tumblr or twitter and your job – you’re likely to have a lot of trouble focusing on one task at a time.

A 2009 study found that people who multitask between media have a harder time filtering information. Researcher Eyal Ophir told Stanford News, “High multitaskers are always drawing from all the information in front of them. They can’t keep things separate in their minds.” Every time you switch between tasks or projects, you lose focus in the transition and a little interference lingers from the thing you just left.

Multitasking within social media also trains you to give up control of your own attention. Going through life ready to drop everything for a Facebook notification or new email teaches your brain to take a hands-off approach to focus. If something new and exciting might pop up at any second, it becomes harder to decide to fully focus on the thing that’s in front of you now.

6. For good or for ill, your internet use can shape your brain.

Your brain develops according to how you use it. And if you don’t use it, you lose it. (Not your whole brain, okay, but the parts you’re not using.)

There’s evidence that if you get your main social fix online instead of IRL, the parts of your brain responsible for processing speech and facial expressions may physically shrink. (A pdf of that study is here.) If you like to share a lot about yourself online, the regions of the brain that connect emotions to decision-making and that respond to rewards may be larger. Whether it’s nature or nurture, the chicken or the egg – the effect of your choices or a genetic predisposition – it shows up in the anatomy of your brain.

7. Googling keeps your brain on its toes.

You’d think that when you get good at doing something, it becomes easier for you to do. And this is usually how it works – new tasks take lots of attention and brainpower, but mastery means you can coast.

But with Google, this doesn’t seem to be the case. A study compared internet novices to seasoned pros and found that when newbies Google, their brains look like they’re reading. But web-savvy searchers use more of their brain, including regions that control decision making and complex reasoning. The researchers think this suggests that “internet searching remains a novel and mentally stimulating process even after continued practice.”

8. Screen light keeps you awake.

Day=light, night=dark. Nothing crazy here. But it’s more than basic knowledge – it’s how your brain knows what to do. Bright light tells your brain to stay awake by suppressing the production of melatonin, the hormone that controls your sleep cycles. And research going as far back as 1958 shows that blue light – like what’s blasting out of your computer screen – has the strongest effect.

The bright light from your computer screen or e-reader could be costing you an hour of sleepy time a night. (If shutting down a few hours before bed feels like too big a sacrifice, install software like fl.ux that tints your screen red after sunset to diminish this effect.)

9. Selfies can boost your self-esteem.

The hand-wringing about selfies has been endless. But research shows that posting pictures of yourself online, especially in a supportive community, can actually help you feel better about the way you look.

Viewing pictures of yourself and other fabulously real people can counter the impossible beauty standards set by the media. A study of NSFW selfie-blogging communities on Tumblr found that participants felt better about their appearances, more connected to their own bodies, and more generous and approving of others’ bodies as well. So put that crooked grin up on Instagram – you’re gorgeous.